CN106517750B

CN106517750B - Device and method for stabilizing a sheet made of hard brittle material

Info

Publication number: CN106517750B
Application number: CN201610816559.0A
Authority: CN
Inventors: M·洛茨; T·罗斯迈耶; C·欧特曼; V·塞伯特
Original assignee: Schott AG
Current assignee: Schott AG
Priority date: 2015-09-11
Filing date: 2016-09-12
Publication date: 2021-05-25
Anticipated expiration: 2036-09-12
Also published as: US20170073264A1; JP6538632B2; US11155496B2; DE102016116259A1; JP2017061403A; CN106517750A

Abstract

The invention relates to a method and a device for stabilizing the position of a sheet-like element (1) made of hard, brittle material during transport along a transport path. For this purpose, the element (1) is guided through a roller channel having three rollers (4, 5, 6).

Description

Device and method for stabilizing a sheet made of hard brittle material

Technical Field

The present invention relates generally to stabilizing the position of a sheet of material. More particularly, the invention relates to stabilizing the position of a sheet of hard brittle material, particularly a sheet made of glass.

Background

In the production of thin glass, a glass sheet or ribbon is drawn from a melt. Such glass ribbons can be deflected and wound up edgewise or edgeless in the horizontal conveyance direction to form rolls.

In the next process step, the glass, with or without edges, can be wound from one roll to another again or unwound from a roll to be separated into any freely shaped strip or sheet.

From at least two tape portions or a number of sheets, a new roll can be prepared again. Here, the parts or sheets are often joined together by means of an adhesive.

One or more non-abrasive plastic films may be disposed between the various layers of the glass ribbon as the continuous glass ribbon is wound to protect the surface of the glass ribbon from contamination and/or mechanical damage.

During the transport, the individual sheets can also be arranged, for example, on a wound adhesive film serving as a carrier tape. Furthermore, a new roll may also be formed from at least two strip portions or a number of sheets.

In addition, the sheet material can also be inserted between the two carriers. The support may also be functionalized, for example by a functional coating, such as an optical, electronic or electro-optical layer.

Instead of winding, it is also possible to arrange the glass ribbon or the adhesive film with the various sheets thereon in a serpentine configuration.

A conveyor having rollers is used to convey the glass ribbon. Patent document US 7,461,564B2 shows various arrangements of rollers, for example in fig. 6 a channel consisting of three rollers (Schikane).

During the conveyance of the glass ribbon, instability in the direction of the glass ribbon may occur due to undulations along or transverse to the direction of conveyance. If the glass ribbon is subsequently wound, this instability may lead to deviations in the winding levelness (Wickelspiegel) and damage or even breakage of the glass.

Here, the winding horizontality refers to an end surface structure of the wound glass ribbon. The end faces of the cylinder formed by winding the glass ribbon are formed here by the mutually overlapping edges of the glass ribbon. Ideally, the edges of the glass ribbon are flush with one another in the wound state, so that the two end faces are completely flat.

However, undulations of the glass ribbon perpendicular to the direction of conveyance can cause the glass ribbon to move transversely with respect to the direction of conveyance or the longitudinal direction of the ribbon. As a result of this movement, the edges of the glass ribbon are no longer flush with one another in the wound state. Because the individual layers of the glass ribbon are offset from each other, both end faces (Stirn-und) of the glass ribbon are wound

) Are no longer flat.

If there is, for example, an adhesive film between the various layers of the glass ribbon, the adhesive film may protrude beyond the edges of the glass ribbon. In this case, the quality of the winding levelness is illustrated by the relative offset of the individual glass layers.

The lower the quality of the winding levelness, i.e., the greater the relative displacement of the individual glass layers from one another, the more stress states occur in the wound glass ribbon. This can lead to problems and even to glass breakage and thus glass breakage, in particular in the subsequent processing steps.

It is therefore desirable to achieve as high a quality as possible for the winding levelness, which is measured here over a plurality of glass thicknesses. This occurs in the following context: in particular thin glass, i.e. glass which is to be transported and processed to a thickness of not more than 300 μm.

Disclosure of Invention

The object of the invention is therefore to provide a device and a method which make it possible to stabilize the transport and direction of the glass ribbon and thus to improve the quality of the winding levelness.

The object of the invention is given by the subject matter of the independent claims. Preferred embodiments of the invention are given in the respective dependent claims.

The invention therefore proposes a method for stabilizing the position of a sheet-like element made of hard, brittle material, in particular glass, during transport along a transport path, the element having an upper face and a lower face and two outer edges, the method comprising the following steps:

providing a sheet-like element of given material type and thickness,

a deflection device is provided, which has at least one deflection element by means of which a sheet-like element made of a hard, brittle material is deflected in its transport path with a direction component perpendicular to the surface by bending the sheet-like element.

The deflecting element is pivotably or movably supported in a direction perpendicular to the element surface, so that the position of the surface of the sheet-like element can be changed by the movement of the deflecting element.

Preferably, the deflection means has a plurality of deflection elements, particularly preferably three such elements, in particular a first mechanically acting element having a first surface, a second mechanically acting element having a second element surface and a third mechanically acting element having a third element surface.

In a preferred embodiment, the first element is arranged at a distance from the third element, while the second element is arranged between the first element and the third element, wherein at least one of the elements, preferably the second element, is movably supported by a rocker bearing, thereby enabling the movably supported element to pivot about a pivot axis perpendicular to its axis of rotation.

Furthermore, the method according to the invention may comprise: the sheet-like element is guided along a transport path, which sheet-like element passes at least once over or under at least one deflection element.

In the case of a plurality of deflection elements, the sheet-like element is here bent in a wave-like manner over three of the elements and each side is in contact with the element surface.

These deflecting elements are mechanically acting elements and apply a force or moment to the sheet-like element.

In a particularly preferred embodiment of the invention, the mechanical action element is constituted by a roller. Therefore, hereinafter, the rollers will be referred to without loss of generality.

The rollers can be in particular rollers of one-piece design, but can also consist of a plurality of elements spaced apart from one another.

Such a mechanically acting element may also be another form of deflecting element, such as a magnetic levitation element or a vacuum element.

If the sheets arranged on the carrier are to be processed, the elements can be designed such that they come into contact only with the carrier, i.e. only between the individual sheets.

The second roller can in particular be located below the level of the connecting line from the first roller to the third roller, in order to achieve an undulating or undulating guidance of the component on the rollers.

In order to reduce the risk of breakage of the sheet-like element, the decisive factor is the geometry of the roller channel formed by the three rollers. The geometry is described by the spacing of the two outer rollers and the position of the surface of the intermediate roller below the line of connection of the two outer rollers.

In a preferred embodiment of the method according to the invention, the distance between the first roller and the third roller will therefore be selected in dependence on the thickness of the sheet-like element.

The sheet-like member to be conveyed may have irregularities of its surface. This can be a wave-like structure which is limited by production technology or which occurs only upon impact on the roll.

In a further embodiment of the method according to the invention, the second roller is therefore moved in the vertical direction in order to compensate for surface contours, in particular shaft irregularities.

The method according to the invention is preferably used for conveying glass ribbons. In a further embodiment of the method according to the invention, the following steps are therefore also included after the introduction of the sheet-like element: -winding the sheet elements, where the sheet elements are stacked on each other after being wound.

As a target parameter of the winding, the quality of the winding levelness is particularly important.

The embodiments of the method according to the invention described so far do not include measures which enable an actively controlled improvement of the winding levelness quality.

In a particularly preferred embodiment of the method according to the invention, the following steps are therefore also included:

during the guiding of the sheet-like element, the deviation of the outer edge of the sheet-like element from a straight course is monitored by means of a sensor or a monitoring device,

during guiding of the sheet-like element, deviations of the course of the outer edge of the sheet-like element from a straight course are corrected by pivoting the second roller and/or adjusting the position of at least one of the first, second and third rollers in the vertical direction.

The method according to the invention is preferably used in the following environment: i.e. the sheet-like element is a glass ribbon of a predetermined thickness, which is guided in its longitudinal direction by means of rollers.

When applying the method according to the invention to a glass ribbon, it is particularly preferred that after the glass ribbon is guided by means of rollers, the glass ribbon is wound into a roll, wherein the winding levelness quality in the form of an average deviation of the outer edge position from the average value of the outer edge position is less than 2.0mm, preferably less than 0.5mm, particularly preferably less than 0.2 mm.

The invention also relates to an apparatus for stabilizing the position of a hard brittle material, particularly a glass ribbon, during conveyance along a conveyance path. The device comprises a deflection mechanism having at least one deflection element by means of which a sheet-like element made of hard, brittle material is deflected on its transport path with a component of direction perpendicular to the surface by bending the sheet-like element, wherein the deflection element is pivotably or movably supported in a direction perpendicular to the surface of the element, so that the position of the surface of the sheet-like element can be changed by the movement of the deflection element.

Preferably, the deflection mechanism comprises three deflection elements, in particular a first mechanically active element having a first element surface, a second mechanically active element having a second element surface and a third mechanically active element having a third element surface, wherein,

the first element is spaced apart from the third element by a distance,

the second element is arranged between the first element and the third element, and here,

at least one of said elements, preferably the second element, is movably supported by the rocker bearing, thereby enabling the element to pivot about a pivot axis perpendicular to the axis of rotation, where,

the sheet-like element is guided along a transport path over or under at least once at least one deflection element, wherein the sheet-like element is bent in such a way that each surface comes into contact with an element surface and bends in a wave-like manner.

In a particularly preferred embodiment of the device according to the invention, the mechanically acting element is a roller. The rollers can be designed in particular as cylinders and in one piece, but can also consist of a plurality of elements spaced apart from one another.

Furthermore, the mechanically acting element may also be a deflecting element of the magnetic levitation or vacuum element type.

In a preferred embodiment, the apparatus according to the invention comprises a fourth roller on which the sheet-like element is wound after passing through the roller channel.

In a further development of the device according to the invention, the device has a sensor which is designed to detect a deviation of the direction of travel of the sheet-like element from a straight course. In this embodiment of the device according to the invention, the device furthermore comprises a monitoring device which is designed to correct the determined deviation of the course of the sheet-like element from the straight course by adjusting the at least one roller such that the quality of the winding levelness in the form of an average deviation of the outer edge position from the average value of the outer edge position is less than 2.0mm, preferably less than 0.5mm, particularly preferably less than 0.2 mm.

The invention also relates to a glass manufacturing system comprising a thermoforming device for forming a sheet-like glass article, in particular a glass ribbon, and an apparatus according to the invention for stabilizing the position of the sheet-like element during transport along a transport path.

In addition, the invention also provides a roll made of glass, the thickness of which is less than 300 μm and which can be produced with the method for stabilizing the position of a sheet-like element according to the invention. By stabilizing the position of the strip transversely to the transport direction according to the invention, a particularly flat winding levelness can be conditionally achieved. According to a preferred embodiment of the invention, the average deviation of the position of the edges of the superimposed layers of the glass ribbon is less than 2.0mm, preferably less than 0.5mm, more preferably less than 0.2 mm.

In one embodiment of the invention, the glass ribbon is chemically tempered during the method according to the invention. The chemical tempering is performed by ion exchange. The chemical tempering treatment comprises at least the following method steps a) to c):

a) preheating the glass ribbon at the temperature of 300-550 ℃,

b) chemical tempering of the glass ribbon is realized through ion exchange in the surface area within the tempering temperature range of 300-550 ℃,

c) the tempered glass ribbon is cooled to a temperature <150 ℃.

After the chemical tempering treatment, the glass ribbon is wound using the method according to the invention.

According to one embodiment of the tempering treatment, the thickness of the glass ribbon is <300 μm, preferably 30-144 μm. The glass ribbon is chemically tempered by ion exchange. In particular, sodium and/or lithium ions in the region of the surface of the glass ribbon are at least partially replaced by potassium ions. For this purpose, potassium ions are applied to the glass ribbon before step a) and/or in step b).

First, the glass ribbon is heated in step a) to a temperature in the range of 300-550 ℃. The thin glass is here preheated to the temperature at which chemical tempering takes place in step b). By preheating to tempering temperature, it is possible to prevent: in thin glass, stress is formed in the glass due to an excessive temperature difference during chemical tempering or due to rapid heating of the glass, and the glass is broken in the tempering process. Such preheating can be carried out, for example, in a continuous furnace. This variant is particularly suitable when the glass ribbon is already present in the form of a glass roll and is unwound and then should be wound up again to form a glass roll. Thus, this tempering process can be integrated in the reel-to-reel process.

In a further variant, the glass ribbon already has a temperature in the tempering temperature range, for example by means of a drawing process. The active heating of the glass ribbon in step a) can therefore be dispensed with.

After preheating the thin glass to the tempering temperature in step a), the thin glass is chemically tempered by ion exchange on the glass surface in step b). The ion exchange as used herein means: part of lithium ions and/or sodium ions located in the vicinity of the glass surface is replaced with potassium ions previously applied to the glass surface.

In a subsequent step c), the glass ribbon that has been tempered is cooled to a temperature <150 ℃. The treatment steps a) to c) are carried out in a continuous furnace.

In one embodiment of the tempering treatment, in step a), the glass ribbon is heated in a continuous furnace with a temperature gradient. This enables the glass ribbon to be heated particularly perfectly and thus avoids stresses in the glass. The furnace used in step a), hereinafter simply referred to as pre-furnace, has the following temperature gradient: the temperature gradient increases from one end of the furnace to the other. Thus, the furnace has a low temperature T at one end_UAnd has a high temperature T at the other end_OWherein, T_u<T_o. The temperature of the furnace is raised relative to the direction of conveyance of the glass ribbon, i.e., the glass ribbon enters the furnace through the furnace end having a temperature Tu. It has been demonstrated that: at a low temperature T below 150 DEG C_UAnd a high temperature To in the range of 350-. Preferably, the high temperature To is equal To the tempering temperature T_H。

In step b), chemical tempering of the glass ribbon is achieved by at least partially replacing sodium and/or lithium ions located in the vicinity of the surface of the glass ribbon with potassium ions. Here, potassium ions are applied to the surface of the glass ribbon prior to the tempering treatment. The desired penetration depth (depth of layer DOL) and intensity increase Cs of the potassium ions can be set by the process parameters tempering temperature T_HAnd tempering time t_HTo adjust. Here, tempering time t_HI.e. the residence time in the tempering furnace, can be adjusted by the feed rate of the glass ribbon and the length of the tempering furnace or the length of the transport path through which the glass ribbon passes in the tempering furnace. Suitable materials for the rolls in the tempering furnace are, in particular, glass, ceramics, metals or composite materials composed of these materials.

After the tempering step b), the tempered glass ribbon is cooled in step c. To avoid stresses in the tempered glass, it is preferred to use a furnace with a temperature gradient. The furnace is preferably designed as a continuous furnace and has at one end a furnaceHaving a high temperature T_OAt the other end with a low temperature T_U. The tempered glass ribbon is guided through a furnace where it is subjected to a high temperature T_OIs introduced into the furnace, cooled therein and brought to a temperature T_UAnd exits the furnace. It has been demonstrated that: low temperature T_UParticularly advantageously below 150 ℃. High temperature T of the furnace_O350-550 ℃. It has been demonstrated that: when high temperature T_OEqual to the tempering temperature T in the following step b)_HIs particularly advantageous.

In one embodiment of the tempering process, the same continuous furnace with a temperature gradient is used in step a) and step c). Since only one furnace is required here, both a compact design of the device and energy savings can be achieved.

Such tempering treatment during the transport according to the invention can be carried out immediately after the drawing treatment before being wound into a glass roll. And cleaning, tempering and drying the stretched glass ribbon. Since the glass is drawn at high temperature and therefore has a considerably high temperature before the tempering process, the duration of the preheating may be shortened or even this step may be omitted completely. This is particularly suitable for the following cases: the glass ribbon has a tempering temperature T after the drawing process_HA temperature within the range.

In one variant, potassium ions can be applied to the surface of the glass ribbon by guiding the glass ribbon through a potassium-containing melt in step b). The melt may contain, for example, potassium nitrate.

Furthermore, the potassium-containing salt solution can alternatively be applied on the top and bottom of the glass ribbon, i.e. on the upper and lower side of the glass ribbon. In this case, the application of potassium ions will be performed before the glass ribbon is guided through the tempering furnace. The potassium-containing salt solution is preferably applied before preheating the glass ribbon (step a)). In addition to preheating the glass ribbon, the solvent will therefore also be evaporated in step a).

In this case, the potassium-containing salt solution may be applied to the surface of the glass ribbon by a spray process. The potassium-containing solution is preferablyIs salt KNO₃、K₃PO₄Potassium chloride, potassium hydroxide and/or K₂CO₃An aqueous solution of (a).

The following glass roll can thus be obtained: it comprises alkali-containing, chemically tempered, thin glass with a thickness <300 μm. It is thus also possible to obtain rolls of glass comprising a chemically tempered thin glass having a thickness only in the range of 30 μm to 145 μm.

The glass ribbon is enriched with potassium ions, particularly in the region near the surface. In one embodiment, the depth of penetration DOL is up to 30 μm. Preferably, the penetration depth DOL of the glass of the roll is in the range of 2 to 8 μm, particularly preferably in the range of 3 to 5 μm. Glass having such a penetration depth has a sufficiently high strength and is therefore used, for example, as cover glass for touch screens in mobile electronic devices. While for this relatively small exchange depth only a short tempering time is required, which is advantageous from a process technology point of view. Thus, tempering time t_HCan be reduced by at least one hour, or even<For 30 minutes. Even the tempering time t_HIn the range of 10 to 20 minutes is also possible.

Tempering time t as short as possible_HThe solution of (a) is more important for the tempering process integrated in the glass ribbon transport than the conventional process in which the glass is held still in the salt solution during the ion exchange. Thus, in the integrated tempering process, the tempering time t is longer_HSlowing down the entire transport process and requiring very low feed rates and/or long transport routes in the tempering furnace.

Drawings

The invention will be explained in more detail below on the basis of further embodiments and with reference to the drawings. In the drawings, like reference numerals designate identical or corresponding elements. Wherein:

fig. 1 shows the basic structure of a device for conveying sheet-like elements made of hard, brittle material;

FIG. 2 shows a side view of a roller channel;

FIG. 3 shows another side view of the roller channel;

FIG. 4a shows a side view of a rigidly supported roller and a glass ribbon to be conveyed;

FIG. 4b shows a side view of the roll with rocker pedestal and glass ribbon to be conveyed;

FIG. 5 shows a top view of a roller with a rocker pedestal according to the present invention;

figure 6 shows a device for feeding sheet-like elements with a store for the elements in the raw state and the elements in the wound state;

fig. 7 shows the device according to fig. 6, which is additionally provided with a cutting device;

fig. 8 shows the device according to fig. 7, where the wound roll has been removed;

fig. 9 shows the device according to fig. 6 with the roller from which the sheet-like element is unwound and the element in a wound state;

FIG. 10 is a schematic view showing a tempering process in which a glass ribbon to be tempered is passed through a molten salt;

fig. 11 shows a schematic view of a further embodiment of the invention, in which the tempering process is directly followed by a drawing process for forming a thin glass ribbon;

FIG. 12 schematically illustrates another embodiment of a tempering process in which potassium ions are applied to the glass ribbon in the form of an aqueous solution;

fig. 13 shows a schematic representation of a tempering process, in which method steps a) and c) are carried out in the same furnace;

FIG. 14 shows three curves with cubic splines describing the run of the glass ribbon on three rolls.

Detailed Description

Fig. 1 shows the basic components of an apparatus for conveying a sheet element 1 made of hard, brittle material. The element 1 has, due to its sheet-like shape, opposite upper and lower faces 10, 11, the

faces

10, 11 extending generally parallel to each other.

According to a particularly preferred embodiment, the hard brittle material is glass. Furthermore, the element 1 is a glass ribbon 100. The glass ribbon 100 is moved in its longitudinal direction 101 by means of the conveying device 7. In this case, the component 1 or the glass ribbon 100 passes through a mechanism formed by a first roller 4, a second roller 5 and a third roller 6, the first roller 4, the second roller 5 and the third roller 6 together forming a device 2 for stabilizing the component 1 or the glass ribbon 100. The apparatus 2 forms a roller channel.

The use of rollers is a particularly preferred embodiment of the invention. As explained previously, various other forms of mechanically acting elements may be used in place of the rollers.

The element 1 is bent over the

rollers

4, 5, 6. The glass ribbon 100 is guided in such a way that the element 1 passes at least once with its at least one

side

10, 11 over each of the three

rollers

4, 5, 6. Specifically, ribbon 100 is guided with side 11 over

rolls

4 and 6 and with opposite side 10 over intermediate roll 5. Since the element 1 is guided with both sides at least once over the

rollers

4, 5, 6, the strip will acquire a wavy or undulating course in the roller path.

The first roll 4 has a surface 40, the second roll 5 has a surface 50, and the third roll 6 has a surface 60.

Specifically, the glass ribbon 100 travels first over the first roller 4 with the lower face 11, then over the second roller 5 with the upper face 10, and finally over the third roller 6 with the lower face 11, thereby bending the glass ribbon 100. The curvature of the

surfaces

10, 11 running over the

rollers

4, 5, 6 is concave, while the opposite surface is convex. Tensile stresses, which are determined by the radius of curvature, occur on convex curves, while the respective surfaces running on the roll surfaces 40, 50, 60 are subjected to compressive stresses in the region of the concave curve. The latter is not dangerous and does not lead to any breakage.

In order to move the glass ribbon 100 past the

rollers

4, 5, 6, a conveyor 7 is provided. With this conveying device 7, on the one hand the element 1 or the glass ribbon 100 is moved and on the other hand a tensile force is also exerted on the element 1 in the direction of movement, so that both faces 10, 11 are subjected to a tensile stress of at least 2 MPa. This tensile stress is superimposed on the tensile stress induced on the upper or lower faces 10, 11 facing away from the rollers as a result of the bending on the respective roller, to form a resultant tensile stress.

According to one embodiment of the invention, the pulling force is exerted on the component 1 by pulling the conveyor belt 8, which is located downstream of the

rollers

4, 5, 6 in the conveying direction and to which the component 1 is attached. The components 1 can be applied to the conveyor belt 8 by suction in particular. According to this embodiment of the invention, the conveyor belt 8 is a vacuum conveyor belt. In order to generate the pulling force by driving the conveyor belt 8, a device may be used to fix the component 1. A simple way of doing this is to provide a further conveyor belt 9 of the application element 1. In particular, the further conveyor belt 9 can also be a vacuum conveyor belt.

As previously mentioned, three

rollers

4, 5, 6 in the form of roller channels form an integrated device 2 for stabilizing the element 1 or the glass ribbon 100. By means of the main shaft, the axes of the three

rollers

4, 5, 6 can be adjusted in the horizontal direction and in the vertical direction. According to the invention, the roll axis must not be tilted during the adjustment operation.

The

rollers

4 and 6 are spaced apart by a horizontal distance d (fig. 3, 4). In the present invention, the distance d is between 50mm and 500 mm.

The width of the

rollers

4, 5, 6 used is 1000 mm. The radius of the

rollers

4, 5, 6 lies between 10mm and 200mm, where the rollers can be replaced.

The material chosen for use on the surface of the

rolls

4, 5, 6 was EUROTEC-AS 84656EPOM, 70 shore a.

The second or intermediate roller 5 can be arranged at a lower position below the plane of the component 1 or of the glass ribbon 100 during the conveyance by a height h (fig. 3 and 4). According to the invention, the height difference is 0-300 mm. The three

rollers

4, 5, 6 of the apparatus 2 form a roller channel as the second roller 5 is lowered relative to the

rollers

4 and 6. This lowering is shown by the position of the axis of rotation, as shown in the figure.

Fig. 2 and 3 each show a roller channel of this type, in which the sheet-like element 1 or the glass ribbon 100 is passed over the three

rollers

4, 5, 6 in such a way that the glass ribbon 100 runs over the

rollers

4 and 6 and under the roller 5. The contact angles are marked for each of the three

rolls

4, 5, 6. The contact angle being passed from the belt 100 to the respective rollerThe first and last contact points are determined by drawing a straight line to the center point of the roll. The angle enclosed by these two lines is the contact angle. The contact angle formed on the first roll 4 is alpha₁The contact angle on the second roller 5 is alpha₂The contact angle on the third roller 6 is alpha₃。

The distance between the

rollers

4 and 6 is reduced in fig. 3 compared to fig. 2. This will result in a larger contact angle alpha on the second roller 5₃。

The height above the base plate to convey the glass ribbon 100 is 900 to 1000 mm.

The conveying speed of the glass ribbon 100 is 3 to 30 m/min.

When the sheet-like element 1 comes into contact with one of the

rollers

4, 5, 6, buckling of the element may be caused (Stauchung). This is shown in fig. 4a for a rigidly supported second roller 5. The second roller 5 is supported by a rigid bearing 51. The glass ribbon 100 is conveyed in its longitudinal direction 101 and impinges on the second roller 5. Before the second roller 5, a wavy buckling 110 is formed. This buckling is severe for the rigidly supported second roll 5, which entails a high risk of breakage.

Thus, according to the present invention, at least one of the

rollers

4, 5, 6, preferably the second roller 5, is movably supported so that the roller can respond to variations in orientation along the glass ribbon 100 (Ausrichtung) and thus can control the orientation of the glass ribbon. Fig. 4b shows such a movable support of the counter roll. The second roller 5 is movably supported by means of a rocker shaft support 52. The glass ribbon 100 is conveyed in its longitudinal direction 101 and impinges on the second roller 5. Thereby again forming a buckling 111. But the buckling will be smaller because the second roller 5 will be deflected upwards due to its movable support. The risk of breaking the glass ribbon 100 can be significantly reduced due to this smaller buckling.

The movable support of the second roller 5 may be passive. This means that the support responds only to the unevenness of the glass ribbon 100 by allowing the rollers to yield.

However, the movable support of the second roller 5 can also be designed to be active. In this case, sensors or monitoring devices are additionally provided which detect irregularities in the glass ribbon 100 before it contacts the second roller 5 and, by means of a control device, cause the second roller 5 to change its position. By the change in position of the second roller 5, a corresponding force or torque is applied to the glass ribbon 100. Here, the lateral position of the edge of the glass ribbon exiting from the channel can be adjusted by tilting the roller 5. By this inclination it is also possible to obtain an angle between the edge of the introduced belt portion and the edge of the already passing belt portion.

The sensor may also be adapted to detect irregular orientation of the edge of the glass ribbon perpendicular to the direction of conveyance. This wavy course is called camber

In response to the detected deviation of the edge profile from the straight profile, the spatial position of one or more of the

rollers

4, 5, 6 can be changed by means of the control device in order to correct the edge profile by means of the force or moment applied to the glass ribbon and to stabilize the profile of the ribbon. These corrective measures will improve the quality of the winding levelness of the glass ribbon in the wound state when the glass ribbon 100 is wound to form a roll in a later processing step.

The occurrence of irregular band runs can be detected by means of the method disclosed in the patent DE102015108553 of the applicant.

In this way, it is possible to detect processing errors of the material web which is moved in the longitudinal direction during the production process and is preferably designed as a thin glass ribbon. Such processing errors can result in specific geometric defects in the material web. A curve which is characteristic of a characteristic parameter of the material web and which is based on the longitudinal coordinate and is influenced by the defect is detected, wherein the curve runs in a lateral direction relative to the longitudinal direction. Then, a processing error is determined from the curve of the characteristic parameter.

Fig. 5 shows the second roller 5 with the rocker bearing 52 in a plan view. The second roller 5 rotates about a roller axis 53. The glass ribbon 100 is conveyed in its longitudinal direction 101 below the second roller 5. Rocker pedestal 53 allows second roller 5 to move perpendicular to the ribbon, i.e., perpendicular to the plane of the drawing, and thereby give way to irregularities on the surface of ribbon 100, thereby reducing the risk of ribbon 100 breaking.

The support of the intermediate roller 5 can also be configured such that the roller 5 rotates about an axis parallel to the conveying direction. By rotating about an axis extending in this way, irregularities in the course of the strip can be compensated, in which the outer edge is inclined to the transport direction, which in the subsequent winding would result in a low quality of the winding levelness. However, by the present invention, the average deviation of the edge positions of the overlapping layers of the glass ribbon can be limited to less than three times the thickness of the glass ribbon.

Fig. 6 shows a device according to the invention with a roller channel consisting of

rollers

4, 5, 6. The sheet-like element 1 or the glass ribbon 100 is conveyed from left to right in the drawing by two conveying

devices

7 and 70. The sheet-like element 1 or the glass ribbon 100 is drawn from the store 17. In this case of the glass ribbon 100, a viscous heated glass 19 is accommodated in the reservoir 17, which leaves the reservoir 17 in the form of a glass ribbon at the bottom of the reservoir 17 due to gravity. After exiting the reservoir 17, the glass ribbon 100 is advanced by the

conveyors

7, 70 and through a roller

path including rollers

4, 5, 6. Upon exiting the conveyor, the glass ribbon 100 is wound so that the ribbon is eventually in a wound state 103.

In fig. 6, the vertical position of the intermediate or second roller 5 is adjusted by means of a positioning device 22. This adjustment can be either actively or passively operated, as will be described later.

Fig. 7, 8 and 9 show another possible application of the device 2 according to the invention.

Fig. 7 shows the device according to fig. 6, but supplemented with a cutting device 30. The cutting device 30 will sever the glass ribbon 100, for example, when the glass ribbon 100 reaches a predetermined diameter in the wound state 103. The roll around which the glass ribbon 100 is wound then needs to be replaced.

To prevent the glass ribbon 100 from moving downward toward the ground after leaving the conveyor 7 during the replacement of the roll around which the glass ribbon 100 has been wound, the intermediate roll 5 is moved downward, i.e., lowered, by the positioning device 22. As a result, the path through which the glass ribbon 100 moves becomes longer. Thus, at a constant conveyance speed, this will cause no glass ribbon 100 to fall and thus lose subsequent processing. The state after cutting the glass ribbon 100 during replacement of the rolls for winding the glass ribbon 100 is shown in fig. 8.

Fig. 9 shows the apparatus according to fig. 6, wherein instead of the store 17, the glass ribbon 100 is provided in a wound state 104. The glass ribbon 100 is unwound before passing through the

conveyors

70, 7 and the roller path including the

rollers

4, 5, 6. Thus in fig. 9, the apparatus according to the invention is used in a roll-to-roll process. In such a process, the glass ribbon is unwound from the first roll, processed, and rewound. In a very simple case, such a treatment can also achieve a better level of winding by means of the device according to the invention.

The distribution of tensile stress for the sheet element 1 provided in the form of the glass ribbon 100 can be calculated by simulation. These calculations will use two different types of glass, AF32 and D263. The two types of material properties are as follows:

AF32

young's modulus E ═ 74.8Gpa

Poisson coefficient v is 0.238

Density rho 2430kg/m³

D263

Young's modulus E ═ 72.9Gpa

Poisson coefficient v is 0.208

Density rho 2510kg/m³。

Nine variations are considered in the calculations performed, and here, the variations differ in glass type, glass thickness, roll spacing, roll drop and contact angle. These variants are summarized in the following table.

The roll gap is the distance between the axes of symmetry of the two

outer rolls

4 and 6.

The roll lowering amount refers to describing the position of the intermediate roll 5 as a height difference between the axis of symmetry of the second roll 5 and the plane in which the sheet member 1 or the glass ribbon 100 lies when being conveyed.

The contact angles listed in the above table are the contact angles α of the glass ribbon 100 on the intermediate roll 5₂. The contact angle increases with decreasing roller spacing and increasing amount of lowering of the second roller 5.

All variants 1-9 listed in the above table will be calculated according to the following steps.

In a first step, the intermediate roller 5 will be lowered by the amount given in each case. During the lowering of roll 5, two maximum tensile stresses (zugspannnumxiaxima) are generated on the upper side 10 of ribbon 100 and one maximum tensile stress is generated on the lower side 11 of ribbon 100. These maxima do not exceed 26.6 MPa.

Then in a second step, the glass ribbon or roll is accelerated to a feed speed. During this accelerated treatment, a high temporary tensile stress is generated in the glass ribbon 100 at values in excess of 200 MPa.

The third step describes conveying the glass ribbon at a constant conveyance speed. The above temporary tensile stress has disappeared after about 3 to 5 seconds. A steady state is then reached in which the tensile stress in the ribbon 100 does not exceed 27.8 MPa.

The stress distribution in the belt during the moving, i.e. conveying operation, is calculated and compared with the stress distribution in the stationary, i.e. non-moving, belt.

Through the calculations performed, it appears that: the tensile stress distribution in the non-moving belt coincides with the distribution in the moving belt. The maximum magnitude of the tensile stress differs only by about 1MPa between the moving and the non-moving belt, which corresponds to an increase in tensile stress of less than 5%.

From a comparison of the variants 1 to 6, it can be seen that at a glass thickness of 50 μm, the magnitude of the tensile stress is approximately 26Mpa, depending only on the diameter of the roll.

The size of the area where tensile stress occurs will increase as the roll spacing decreases.

In addition, the size of the region where tensile stress occurs will also increase as the amount of roll drop increases.

Comparing variants 1 to 3 with

variants

7 and 8, it can be seen that: in the case of larger glass thicknesses (100 μm in variants 7 and 8), the magnitude of the tensile stress is also dependent on the geometry of the roll channel, i.e. on the combination of the respective selected roll spacing and roll drop.

It was not certain that changing the type of glass used (replacing AF32 with D263) could have significant effects. This is because the young's moduli of the two glass types selected are approximately equal.

The glass ribbon 100 is deflected by means of the

rollers

4, 5, 6, which results in a bending force being generated in the glass ribbon 100. The degree of such deflection, and thus the magnitude of the additional generated tensile force in the glass ribbon 100, is indicated by the magnitude of the contact angle. The greater the contact angle, the greater the deflection of the glass ribbon 100 and thus the bending force generated in the glass ribbon 100.

If the glass ribbon 100 were to rest on the roll between the first and last contact points, the glass ribbon would bend along a line L equal to the arc length of the fan shape, with the center angle of the fan shape equal to the contact angle, and the radius of the fan shape equal to the radius of the roll. The glass ribbon is bent along this line L at a bend radius equal to the roll radius. The bend radius is related to the generated tensile force as follows: as the bend radius decreases, the tensile force generated increases.

Hard brittle materials behave differently under a certain load than, for example, ductile materials. Ductile materials, particularly many metals, will stretch under bending or tensile stress up to their yield limit and then tear under a relatively definite load. In contrast, fracture of hard brittle materials does not occur at the strength limit in terms of material properties, but rather at a probability in a statistical sense that depends on the applied tensile stress. The fracture probability parameters (e.g., normal distribution or weber (Weibull) distribution) depend primarily on the processing of the relevant sample, but only slightly on the material compared to ductile materials.

With the aid of the method described in DE 102014110856, in the name of the applicant, for a glass of a given type and thickness, it is possible to determine the bending radius at which the glass will not break with a high probability as a function of the tensile stress applied. In this method, a strip-shaped sample of the material to be tested is fastened at its two ends to a holder. The two holders are then pulled apart from each other, thereby subjecting the sample to a tensile stress. The tensile force that caused the sample to tear was recorded. Such tests will be performed on multiple samples. From the recorded tensile forces, the mean value of the bending radii and the variance thereof corresponding to these tensile forces can be calculated.

The tensile stresses obtained by the simulation described above can be used to determine the minimum bending radius and then, in turn, the geometry of the selected channel formed by the three

rollers

4, 5, 6.

Alternatively, the minimum bending radius as a function of the applied tensile stress can also be determined by means of the method described in DE 102013110803 of the applicant.

In the method, the thin glass is subjected to a stretching force which is less than

Wherein the content of the first and second substances,

the average value of the tensile stress at which a fracture occurs in the surface region of the sample,

is the average value of the tensile stress at break starting from the edge of the reference sample; wherein, Delta_aAnd Δ_eIs that it isMean value corresponds to standard deviation. L is_refAs the side length of the reference sample, A_refIs its area. A. the_APPSurface area of thin glass, L_APPIs the total side length of the opposite edges of the thin glass. Φ is the predetermined maximum failure rate over at least half a year.

In a further method step, the thin glass is bent, wherein the minimum bending radius R and the tensile stress σ_AppThe relationship of (a) to (b) is as follows:

where E is the Young's modulus, t is the thickness of the thin glass, and ν is the Poisson's ratio of the glass.

Even if this method is chosen to determine the minimum bending radius, it is possible to obtain the tensile stress from the above simulation and then to determine in return the geometry chosen for the channel constituted by the three

rollers

4, 5, 6.

The minimum roll radius is set based on the minimum bend radius thus determined because the roll radius is equal to the bend radius of the glass ribbon 100 as previously described.

In order to provide a defined minimum bending radius determined by the roll radius, it is desirable to have the contact angle greater than 0 °. In addition, in order to be able to guide the glass ribbon reliably, it is advantageous if the glass ribbon contacts the rollers not only along a straight line parallel to the roller axis. The contact angles of the embodiments in the above table will be determined by finite element calculations. In a further embodiment, the course of the glass ribbon or generally the sheet-like element in at least one deflection element of the deflection mechanism can be determined using spline functions. For this purpose, at least one interpolation point of the spline function, also referred to as a knot point, is provided on each deflection element. Particularly suitable for this purpose are cubic Spline (kubishcher Spline) functions. The spline function is established by the auxiliary conditions: the surface of the element 1 made of hard brittle material extends tangentially to the surface of the deflecting element at the junction.

The individual method steps of the tempering process are schematically illustrated in fig. 10 to 13. The tempering treatment shown may be integrated in the method according to the invention.

In the embodiment of the tempering process schematically shown in fig. 10, the thin glass has a thickness in the range of 30-144 μm. The arrows here indicate the direction of movement of the glass ribbon 100 conveyed by means of the

rollers

130, 131, 132, 133, 134.

The glass ribbon 100 is first cleaned and dried. The method step is represented by block 140. Subsequently, the glass ribbon 100 passes through a continuous furnace 150. In the continuous furnace 150, the glass ribbon 100 is heated to a temperature in the range of 300 ℃ to 550 ℃ and tempered at a tempering temperature T_HTemperatures within the range exit the continuous furnace 150. The stresses induced in the glass ribbon due to this temperature difference are avoided by the subsequent step b). It has been demonstrated here that: it is particularly advantageous to heat the glass ribbon in a continuous furnace 150 having a temperature gradient. The temperature gradient in the furnace 150 is schematically illustrated by arrows 220. The temperature gradient in the furnace is determined by the low temperature T in the furnace_UAnd high temperature T_OAnd (4) degree limitation. Here, the temperature of the opening of the furnace 150 through which the glass ribbon 100 enters the furnace is T_U. Raising the temperature in the furnace to a temperature T_OSuch that the temperature of the ribbon 100 as it exits the furnace is T_OOr near T_O. Preferably, the temperature T_UIn the range of 20-150 ℃ and/or a high temperature T_OIn the range of 350-550 ℃. By heating ribbon 100 with a corresponding temperature gradient, stresses (spannungsauufbau) in the glass can be avoided. It has been demonstrated that: heating the glass ribbon to the tempering temperature T in the step b)_HThe corresponding temperatures are particularly advantageous.

Furthermore, heating with a temperature gradient may also result in the elimination of stresses in the glass due to the manufacturing process.

The glass ribbon 100 preheated in step a) is guided through a tempering furnace 160 in step b). The toughening furnace has a toughening temperature T within the range of 300-_H. Here, the tempering temperature T_HI.e., the temperature at which ion exchange occurs, depends on the particular glass composition of the glass ribbon as well as the depth of exchange (DOL) to be achieved and the desired compressive stress C_S。

The toughening furnace 160 includes a molten salt (Salzschmelze)170, and the glass ribbon 100 is drawn through the molten salt 170. The molten salt 170 contains potassium ions so that ion exchange occurs in the region near the surface of the glass ribbon, during which sodium and/or lithium ions are replaced by potassium ions.

The rollers 132 of the toughening furnace 160 are in this embodiment located wholly or partly in the molten salt 170, and therefore the material of the rollers 132 should be inert or at least substantially inert with respect to the salt bath. It has been demonstrated that: suitable materials for the roller 132 include glass, metal, and ceramic. Composite materials composed of glass, metal and/or ceramic may also be used.

The speed of movement of the ribbon is adjusted so that the ribbon is maintained in the molten salt for a desired tempering time t_H. The tempering time t_HDepending on the tempering temperature T_HAnd the exchange depth DOL to be achieved. Thus, for example, a penetration depth of 3-5 μm can be achieved in a tempering time period of 10-20 minutes.

After the tempering treatment, the tempered glass ribbon is cooled in a further continuous furnace 180 in step c). Continuous furnace 180 provides slow cooling of glass ribbon 100 therein to avoid stresses in the glass. In the illustrated embodiment, the furnace 180 also has a temperature gradient, which is represented by arrow 221. The furnace 180 has a temperature T at the opening where the glass ribbon 100 enters the furnace 180_O. The temperature in the furnace 180 will decrease with the direction of movement of the glass ribbon 100 such that the furnace has a temperature T at the opening where the glass ribbon 100 exits the furnace_UHere, T_O>T_U. Preferred temperature T_OAt tempering temperature T_HWithin the range of (1).

It has been demonstrated that: cooling to temperatures <150 ℃ is very advantageous.

Fig. 11 shows a variation of this tempering process, in which the tempering technique will be immediately after a stretching process (not shown) for producing the thin glass ribbon 101. Since the glass ribbon 101 has a tempering temperature T after the drawing process_HOr even temperatures above this range, so that the glass ribbon 100 (step) can be omitted in the variant shown in fig. 11a) Preheating. The glass ribbon 101 is merely cleaned and dried and then the method steps b) and c) are carried out analogously to the variant of the tempering process shown in fig. 10.

This variant is therefore very advantageous, in particular from the point of view of energy technology.

The potassium ions needed to perform the ion exchange can be applied to the surface of the glass ribbon 100 in the form of a solution. This is shown schematically in fig. 12. The glass ribbon 100 is first cleaned and dried. In the next step, the glass ribbon 100 is passed through a device 210 for applying a potassium solution 211 on the upper and lower sides of the glass ribbon 100. Preferably the potassium salt bath is an aqueous solution. In the illustrated embodiment, the solution 211 is sprayed on the surface of the glass ribbon.

Next in step b), the thus treated ribbon 100 is passed through a furnace 150 where it is heated to a tempering temperature T_HTemperature within the range whereby the solvent evaporates. The glass ribbon 110 then passes through a tempering furnace 160 having a tempering temperature in the range of 300-. In this step b) an ion exchange takes place, during which the sodium and/or lithium ions in the region near the surface of the glass ribbon are replaced by potassium ions previously applied to the glass surface. Selected residence time t_HDepending on the desired exchange depth DOL.

In fig. 13, a further variant of the method according to the invention is shown, in which the glass ribbon 100 is guided through the same continuous furnace 230 with a temperature gradient in steps a) and c). The furnace 230 has a temperature gradient, shown by arrow 220, with a low temperature T_UAnd high temperature T_O. The glass ribbon 100 enters or exits the furnace 230 through two opposing

openings

231 and 232. Here, the furnace has a low temperature T at the opening 231_UAnd has a high temperature T at opening 232_OHere, T_O>T_U。

According to this variant, the glass ribbon 100 enters the furnace 230 in step a) through the opening 231. During the passage of the glass ribbon 100 through the furnace 230 in step a), the glass ribbon is heated and passes through a glass ribbon having a temperature T_OExit the furnace at opening 232230. In a subsequent step b), ion exchange takes place in the furnace 160. In this variant according to the invention, the toughening furnace 160 has only one opening 161. The tempering roller 131 is designed as a deflection roller in this variant according to the invention in order to change the direction of movement of the glass ribbon 100 by means of the tempering roller.

The ribbon 100 is heated in the furnace 160 to a tempering temperature T_HTo the tempering time t_HThereafter, the glass ribbon 100 exits the furnace 160 through the opening 161. To cool the thus tempered glass ribbon 100, the glass ribbon 100 is drawn into a furnace 230 through an opening 232 in step c). Here, the glass ribbon is slowly cooled to a low temperature T by the temperature gradient of the furnace_UAnd exits the oven 230 through the opening 231.

As will be described in detail below: it is possible to determine the course of the sheet-like element through one or more deflection elements on the basis of a spline function and to determine therefrom a parameter with respect to the occurrence of tensile stress loads. In one embodiment of the invention, for describing the course of the sheet-like element, the actual minimum bending radius is usually determined from the calculated course, i.e. from a spline function. Such an embodiment can be implemented in or by the mechanism for stabilization according to the invention in order to determine the current tensile stress determined by the position of the deflection element or elements. However, this method of determining the minimum bend radius based on spline interpolation can also be generally used as a sample test. Recording and validation by this sample test: the sheet-like element is subjected to a tensile stress exerted on the surface during the sample testing, which tensile stress is defined by the minimum bending radius.

Accordingly, the invention also relates to a method for testing the strength of a sheet-like element 1 made of hard, brittle material, in particular glass, having two

opposite faces

10, 11, in which method:

the element 1 is guided with each of its faces past one or more deflection elements, preferably a total of at least three deflection elements and is bent thereby such that the

faces

10, 11 of the element 1 made of hard brittle material are subjected to tensile stress in the region of their opposite faces 10, 11 in contact with the deflection elements, and

monitoring and determining whether the element 1 has a predetermined breaking strength equal to the applied tensile stress or whether the element 1 breaks under the applied tensile stress, wherein the tensile stress is determined according to the smallest radius of curvature between the knots set on the surface of the deflecting element by a spline function, in particular a cubic spline function.

For this reason, fig. 14 shows three examples. Shown are curves of three spline functions, each representing the course of the sheet-like element 1, in particular the glass ribbon, on a mechanism comprising three deflecting elements in the form of

rollers

4, 5, 6, i.e. corresponding to the embodiments shown in fig. 1-3 and 6-9. These rollers are described in the curve by corresponding functions. The

rollers

4, 5, 6 are not circular, but oval, due to the different dimensions of the abscissa and the ordinate.

In this case, the spline function would be defined by interpolation points or

knots

41, 51, 61 on the roll. Depending on the position of the intermediate roll 5, the situation shown in curves a), b), c) is obtained. The deflection in curve a) is so small that the radius of curvature on the roll 5 is larger than the roll radius. In curve b) the roll radius of the roll 5 matches the radius of curvature at the junction 51. Finally in curve c), at a single junction 51, the radius of curvature of the element 1 at the junction 51 is smaller than the roll radius, since the roll 5 has a greater deflection than the

rolls

4 and 6. In this case, the course of the element 1 can no longer be described by the three

nodes

41, 51, 61 shown. Instead, a certain contact angle is obtained here. The elements rest against the surface of the roll along the relevant arc of a circle, as shown in figures 2 and 3. Here, the minimum radius of curvature of the element 1 will be determined in dependence on the roll radius. Radius of curvature R at a point of the element 1_ESmaller than the radius of curvature R of the deflecting element_UI.e. R_E<R_UIn the case of (2), then a spline function which correctly reproduces the course of the element 1 with respect to the deflecting element with the associated knots (and overall) can be determined as follows:

in this case, at least two nodes are provided, varying their surface at the deflecting elementUntil the radius of curvature of the element 1 matches sufficiently well with the radius of curvature of the surface of the deflecting element. The term "sufficiently good" again means that the deviation is less than the predetermined threshold. The position of the node can be found quickly here by interpolation. A dichotomy is suitable, for example. By means of the dichotomy, the zero point of a suitable function can be found by halving the successive intervals. For this purpose, in particular the difference R in the radius of curvature can be found in a simple manner_E－R_UZero point of (c).

However, this determination of the minimum radius of curvature by the curvature of the surface of the deflecting element does not apply to the

rollers

4 and 6 in curve c). The radius of curvature here can be smaller, if allowed, than on the intermediate roller 5 in the case of only tangential contact. This will result in the

faces

10, 11 being subjected to different tensile stresses. Thus, the sample tests performed do not have the same informative value on both faces, if allowed. In general terms and without being limited to the specific illustrated example, therefore, in a development of the invention the sheet-like element 1 is guided to pass a deflection element at least once per

face

10, 11 and thus subject the opposite face to a tensile stress, where it is verified by means of splines and knots on the deflection element: whether the tensile stresses are equal on both

faces

10, 11 or differ at least by less than a predetermined threshold. In short, the verification is done by means of spline testing: the sample test is symmetrical at a given deflection element position.

Now, according to the course of the element 1 obtained with the spline function in this variant of embodiment of the invention, the position of the deflecting element is changed to match the tensile stress that the radius of curvature has thus exerted due to the deflection on the deflecting element. That is, first the spline function and the knots on the deflection elements are used to check: whether the tensile stresses are equal on both

faces

10, 11 or whether the difference is at least smaller than a set threshold value, wherein if the threshold value is exceeded, the position of at least one deflection element will change as follows: so that the difference in tensile stress on the two faces 10, 11 is reduced. It is particularly suitable here to reduce the spacing between the

deflection elements

4 and 6.

List of reference numerals

1 sheet element

2 device for stabilizing a sheet-like element 1

4 first roll

5 second roll

6 third roller

7 conveying device

8 conveying belt

9 conveyor belt

10 upper side of the sheet element 1

11 lower side of the sheet-like member 1

13 sensor

17 memory

19 sheet element 1 in raw state, glass ribbon 100

22 positioning device for the second roller 5

24 monitoring device

30 cutting device

40 surface of the first roll 4

41.

Node

51, 61

50 surface of the second roller 5

51 rigid bearing of the second roller 5

52 rocker bearing for the second roller 5

53 axis of the second roller 5

60 surface of the third roller 6

70 conveying device

100 glass ribbon

101 longitudinal direction of glass ribbon 100

103 in the wound state after passing through the device 2, the sheet element 1, the glass ribbon 100

104 the sheet-like element 1, the glass ribbon 100, in the wound state before passing through the device 2

110 buckling of glass ribbon 100

111 buckling of the glass ribbon 100.

Claims

1. A method for stabilizing the position of a sheet-like element (1) made of hard, brittle material during transport along a transport path, the sheet-like element (1) having an upper face (10) and a lower face (11) and two outer edges, the method comprising the steps of:

-providing the sheet-like element (1) of given material type and thickness;

-providing a deflection mechanism comprising at least one deflection element by means of which a sheet-like element (1) made of said hard and brittle material is deflected along its transport path with a component in a direction perpendicular to the surface, whereby said sheet-like element (1) is bent;

wherein the deflecting element is a roller comprising a first roller (4), a second roller (5) and a third roller (6), the second roller (5) being pivotable about an axis parallel to the advancing direction and being movably supported in a direction perpendicular to the surface of the sheet-like element (1), such that the position of the surface of the sheet-like element (1) can be changed by the movement of the deflecting element.

2. The method according to claim 1, wherein the sheet-like element (1) is made of glass.

3. The method of claim 1, wherein,

the first roller is arranged at a distance from the third roller and the second roller is arranged between the first roller and the third roller, and wherein at least one of the first roller (4), the second roller (5) and the third roller (6) is movably supported by a rocker bearing, thereby enabling the movably supported roller to pivot about a pivot axis perpendicular to its rotation axis, and the method further comprises the steps of: guiding the sheet-like element along the transport path, whereby the sheet-like element passes at least one of the deflecting elements at least once above or below it; and/or

Wherein the first roll (4) has a first roll surface (40), the second roll (5) has a second roll surface (50), and the third roll (6) has a third roll surface (60).

4. A method according to claim 3, wherein the second roller is movably supported by a rocker shaft support.

5. A method according to claim 3, wherein the distance between the first roller (4) and the third roller (6) is selected on the basis of the thickness of the sheet-like element (1).

6. A method according to any one of claims 1 to 5, wherein the second roller (5) is moved in a vertical direction in order to compensate for irregularities in the surface profile of the sheet-like element (1).

7. The method of claim 6, wherein the irregularity of the surface profile is waviness.

8. A method according to claim 3, further comprising, after the guiding of the sheet-like element (1), the step of winding the sheet-like element (1), wherein the sheet-like elements (1) are stacked on each other after winding.

9. A method according to claim 3, further comprising, before guiding the sheet-like element (1), the step of unwinding the sheet-like element from a roll (104).

10. The method according to any one of claims 3 to 5, wherein the sheet element (1) is a glass ribbon (100) having a thickness D, the glass ribbon (100) being guided in its longitudinal direction (101) past the first roller (4), the second roller (5), the third roller (6); and/or

Wherein the glass ribbon (100) is wound to form a roll after it has passed through the first (4), second (5), and third (6) rolls, wherein a winding horizontality quality, defined as an average deviation of the position of the outer edge from an average of the position of the outer edge, is less than 2.0 mm.

11. The method of claim 10, wherein the winding horizontal mass is less than 0.5 mm.

12. The method of claim 10, wherein the winding horizontal quality is less than 0.2 mm.

13. Method according to claim 10, wherein, during winding, between the layers of the sheet-like element (1) or the glass ribbon (100), a second layer of material is arranged.

14. The method of claim 13, wherein the second material layer is a non-abrasive film and/or an adhesive film.

15. The method according to claim 10, wherein the hard brittle material is an alkali-containing glass and the glass ribbon (100) is chemically tempered during conveyance along the conveyance path; wherein the glass ribbon has a thickness <300 μm and the chemical tempering treatment comprises at least the following steps:

a) optionally, preheating the glass ribbon (100) to a temperature in the range of 300 ℃ and 550 ℃;

b) the tempering temperature T within the range of 350-_H-chemically tempering the glass ribbon (100) by ion exchange in a surface region; and is

c) Cooling the glass ribbon (100) to a temperature <150 ℃;

wherein potassium ions are applied to the upper face (10) and the lower face (11) of the glass ribbon (100) before step a) and/or in step b); in step b), the glass ribbon (100) is heated to the tempering temperature T_H(ii) a And carrying out steps a) to c) in a continuous furnace (150, 160, 180, 230).

16. The method according to claim 15, wherein prior to step a), a potassium salt solution (211) is applied to the upper face (10) and the lower face (11) of the glass ribbon (100); and/or

Wherein the potassium salt solution (211) is an aqueous solution protecting a salt selected from the group consisting of: KNO₃、K₃PO₄、KCl、KOH、K₂CO₃Or mixtures thereof; and/or

Wherein step b) comprises passing the glass ribbon (100) through a potassium-containing molten salt (170).

17. The method according to claim 16, wherein the potassium salt solution (211) is sprayed onto the upper face (10) and the lower face (11) of the glass ribbon (100) prior to step a).

18. The method according to claim 16, wherein step a) comprises passing the glass ribbon (100) through a continuous furnace (150, 230) having a temperature gradient.

19. The method of claim 18, wherein the temperature of the continuous furnace (150) is elevated relative to the direction of conveyance of the glass ribbon (100), and/or wherein the low temperature T of the continuous furnace_U<150 ℃ and high temperature T of the continuous furnace_OIs in the range of 350-550 ℃.

20. The method according to any one of claims 16 to 19, wherein step c) comprises cooling the glass ribbon (100) in a continuous furnace (180, 230) having a temperature gradient, wherein the temperature of the continuous furnace (180) is reduced with respect to the direction of conveyance of the glass ribbon, and/or wherein the low temperature T of the continuous furnace is low_U<150 ℃ and high temperature T of the continuous furnace_OIs in the range of 350-550 ℃.

21. The method of any one of claims 16 to 19, wherein step c) comprises using the same furnace as in step a).

22. The method according to any one of claims 16 to 19, wherein the rolls of the continuous furnace (160) for tempering are made of glass, ceramic, metal or a composite of these materials.

23. Method according to any one of claims 16 to 19, wherein the tempering time t_HThe exchange depth DOL is chosen to reach the range of 1-10 μm.

24. Method according to any one of claims 16 to 19, wherein the tempering time t_HThe exchange depth DOL is chosen to reach the range of 3-5 μm.

25. The method according to any one of claims 16 to 19, wherein the glass ribbon (100) has a thickness < 145 μ ι η.

26. The method according to any one of claims 16 to 19, wherein the glass ribbon (100) has a thickness in the range of 30 to < 144 μ ι η.

27. Method according to any one of claims 16 to 19, wherein it comprises, before guiding the sheet-like element (1), the steps of:

-unwinding the sheet element (1) from a roll (104), and/or-winding the glass ribbon (100) after the chemical tempering such that the glass ribbons (100) are laminated to each other after winding.

28. The method of any of claims 1 to 5, further comprising: determining the course of the sheet-like element (1) on at least one deflection element of the deflection mechanism by means of a spline function, wherein at least one knot of the spline function is defined on each deflection element; and is

Further comprising: determining a minimum bending radius of the sheet-like element (1) from the spline function.

29. The method of claim 28, wherein the spline function is a cubic spline function.

30. A method as claimed in claim 28, wherein the radius of curvature R at the junction of the sheet-like element (1) is such that it is constant_ESmaller than the radius of curvature R of the surface of the deflecting element_UDetermining a spline function that correctly reflects the course of the sheet-like element (1) on the deflection element by defining at least two knots, wherein the position of the at least two knots on the deflection element is changed until the radius of curvature of the sheet-like element (1) matches sufficiently well with the radius of curvature of the surface of the deflection element.

31. The method according to any one of claims 3 to 5, further comprising the steps of:

wherein, during the guiding of the sheet-like element (1), a deviation of the course of the outer edge of the sheet-like element (1) from a straight course is monitored by a monitoring device (24); and is

Wherein deviations of the outer edge of the sheet element (1) from the straight course are corrected during guiding of the sheet element (1) by pivoting the second roller (5) and/or adjusting the position of at least one of the first roller (4), the second roller (5) and the third roller (6) in the vertical direction.

32. Use of a glass roll made of glass produced according to the method of any one of claims 16-31 in a roll-to-roll process, wherein the roll-to-roll process comprises a coating step and/or a process step for component mounting.

33. An apparatus for stabilizing the position of a sheet-like element (1) made of hard, brittle material during transport along a transport path, the sheet-like element having an upper face (10) and a lower face (11) and two outer edges, the apparatus comprising:

-a deflection mechanism comprising at least one deflection element by means of which a sheet-like element (1) made of said hard and brittle material is deflected along its transport path with a component of direction perpendicular to the surface, whereby said sheet-like element (1) is bent;

34. A device as claimed in claim 33, wherein the sheet-like element (1) is made of glass.

35. The apparatus of claim 33, wherein,

the first roller is arranged at a distance (d) from the third roller and the second roller is arranged between the first roller and the third roller, and wherein at least one of the first roller (4), the second roller (5) and the third roller (6) is movably supported by a rocker bearing (52), thereby enabling the movably supported roller to pivot about a pivot axis perpendicular to the rotation axis; and/or

Wherein the first roll (4) has a first roll surface (40), the second roll (5) has a second roll surface (50), and the third roll (6) has a third roll surface (60); and/or

Further comprising a fourth roller on which the sheet-like element (1) is wound after having passed the roller path or unwound from the roll before passing the roller path.

36. The apparatus of claim 35, wherein the second roller is movably supported by a rocker shaft mount.

37. The apparatus of any of claims 33 to 36, further comprising:

a sensor (13) adapted to detect deviations of the course of the sheet-like element (1) with respect to a rectilinear course; and

-monitoring means (24) adapted to correct deviations of the strike of the sheet-like element (1) with respect to a rectilinear strike by adjusting at least one of the first roller (4), the second roller (5), the third roller (6) so as to define a winding levelness quality defined by an average deviation of the outer edge position with respect to an average of the outer edge positions of less than 2.0 mm.

38. The apparatus of claim 37, wherein the winding horizontality mass is less than 0.5 mm.

39. The apparatus of claim 37, wherein the winding horizontality mass is less than 0.2 mm.

40. A glass manufacturing system comprising: a thermoforming device for forming a sheet glass article; and an apparatus according to any one of claims 33 to 36.

41. The glass manufacturing system according to claim 40, wherein the sheet glass article is a glass ribbon (100).

42. A roll made of wound glass, the thickness D of the glass being less than 300 μ ι η, the roll being manufacturable by a method according to any one of claims 1 to 31, in which roll the winding levelness quality, defined by the average deviation of the outer edge position from the average value of the outer edge position, is less than 2.0 mm.

43. The roll of claim 42, wherein the winding horizontal mass is less than 0.5 mm.

44. The roll of claim 42, wherein the winding horizontal mass is less than 0.2 mm.